Typically, an engine cooling system has a pump to circulate coolant used to cool the engine, a radiator to cool the coolant and a bypass to allow coolant to circulate through the engine without being cooled by the radiator. In motor vehicles, a cabin heater is usually, provided so that the coolant warmed by the engine provides heating for any occupants of the vehicle. Additionally, the main engine coolant is often used to cool one or more additional heat exchangers or radiators such as a transmission oil cooler, a fuel cooler or an air-charge cooler. A temperature responsive control valve is provided to control the flow of coolant through the radiator and frequently also to control the flow of coolant through the bypass.
It is an object of this invention to provide a temperature-responsive control valve for use in an engine cooling system that can provide improved control of flows under a variety of engine running conditions.